The Nikkormat FTn was manufactured from 1967 to 1975. It simplified the lens mounting procedure of the rabbit ear Nikkor lenses. The meter coupling pin on the camera still had to be aligned with the meter coupling shoe on the lens, but the lens maximum aperture no longer had to be manually preset on the FTn.
Instead, the lens aperture ring had to be turned back and forth to the smallest aperture (largest f-stop number) and then to the largest (smallest number) immediately after mounting to ensure that the lens and the FTn couple properly (Nippon Kogaku called it indexing the maximum aperture of the lens) and meter correctly. This system seems unwieldy to today’s photographers, but it was more efficient and easier than before, and became second nature to Nikon and Nikkormat photographers of the 1960s and 1970s.
In addition, the FTn improved the metering system to the now classic Nikon 60/40 percent center weighted style. The viewfinder also added +/– over/underexposure metering markers and set shutter speed information.
The FTn also offered a choice (made at purchase time or by replacement at factory service centers) of brighter fixed viewfinder focusing screens: Nippon Kogaku’s standard Type J with central 4 mm microprism focusing aid plus 12 mm etched circle indicating the area of the meter centerweighting or the Type A with central 3 mm split image rangefinder plus 12 mm etched circle.